Touch input device

ABSTRACT

A touch input device includes a display module, a substrate for blocking electrical noise or for separating the display module from a circuit board or battery for operation of the touch input device, and a first electrode disposed on the display module and a second electrode disposed on the substrate. A spacer layer is disposed between the first electrode and the second electrode. A pressure magnitude of the touch is detected based on a capacitance between the first electrode and the second electrode. The capacitance is changed depending on the distance between the first electrode and the second electrode. The display module is bent by the touch, and the distance between the first electrode and the second electrode is changed due to the bending of the display module. The first electrode is disposed on a bendable surface of the display module.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 14/614,086, filed on Feb. 4, 2015, which claims priority toKorean Patent Application No.: 10-2014-0098917, filed Aug. 1, 2014;Korean Patent Application No.: 10-2014-0124920, filed Sep. 19, 2014;Korean Patent Application No.: 10-2014-0145022, filed Oct. 24, 2014; andKorean Patent Application No.: 10-2014-0186352, filed Dec. 22, 2014. Thedisclosures of the aforementioned priority applications are incorporatedherein by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to a touch input device, and moreparticularly to a touch input device which includes a display module andis configured to detect a touch position and the magnitude of a touchpressure.

BACKGROUND OF THE INVENTION

Various kinds of input devices are being used to operate a computingsystem. For example, the input device includes a button, key, joystickand touch screen. Since the touch screen is easy and simple to operate,the touch screen is increasingly being used in operation of thecomputing system.

The touch screen may constitute a touch surface of a touch input deviceincluding a touch sensor panel which may be a transparent panelincluding a touch-sensitive surface. The touch sensor panel is attachedto the front side of a display screen, and then the touch-sensitivesurface may cover the visible side of the display screen. The touchscreen allows a user to operate the computing system by simply touchingthe touch screen by a finger, etc. Generally, the computing systemrecognizes the touch and the touch position on the touch screen andanalyzes the touch, and thus, performs the operations in accordance withthe analysis.

Here, there is a demand for a touch input device capable of detectingnot only the touch position according to the touch on the touch screenbut the magnitude of the touch pressure without degrading theperformance of the display module.

SUMMARY OF THE INVENTION

A touch input device capable of detecting a pressure of a touch on atouch surface may be provided that includes a substrate and a displaymodule. The touch input device further includes an electrode which isdisposed at a position where a distance between the electrode and areference potential layer is changed by the touch on the touch surface.The distance may be changed depending on a magnitude of a pressure ofthe touch. The electrode outputs an electrical signal according to thechange of the distance. A spacer layer is disposed between the referencepotential layer and the electrode.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a configuration of a capacitance typetouch sensor panel and the operation thereof in accordance with anembodiment of the present invention;

FIGS. 2a, 2b and 2c are conceptual views showing a relative position ofthe touch sensor panel with respect to a display module in a touch inputdevice according to the embodiment of the present invention;

FIG. 3 is a cross sectional view of the touch input device configured todetect the touch position and touch pressure in accordance with a firstembodiment of the present invention;

FIGS. 4a to 4f show a touch input device according to a secondembodiment of the present invention;

FIGS. 5a to 5i show a touch input device according to a third embodimentof the present invention;

FIGS. 6a to 6i show a touch input device according to a fourthembodiment of the present invention;

FIGS. 7a to 7e show a pressure electrode pattern according to theembodiment of the present invention;

FIGS. 8a and 8b show a relation between the magnitude of the touchpressure and a saturated area in the touch input device according to theembodiment of the present invention;

FIGS. 9a to 9d show an attachment structure of the pressure electrodeaccording the embodiment of the present invention;

FIGS. 10a and 10b show a touch input device according to a fifthembodiment of the present invention;

FIGS. 11a to 11b show an attachment method of the pressure electrodeaccording the embodiment of the present invention;

FIGS. 12a to 12c show how the pressure electrode is connected to a touchsensing circuit in accordance with the embodiment of the presentinvention;

FIGS. 13a to 13c show that the pressure electrode constitutes aplurality of channels in accordance with the embodiment of the presentinvention; and

FIG. 14 is a graph that, when an experiment where the central portion ofthe touch surface of the touch input device according to the embodimentof the present invention is pressed by the non-conductive object isperformed, represents a capacitance change amount according to a gramforce of the object.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description of the present invention shows aspecified embodiment of the present invention and will be provided withreference to the accompanying drawings. The embodiment will be describedin enough detail that those skilled in the art are able to embody thepresent invention. It should be understood that various embodiments ofthe present invention are different from each other and need not bemutually exclusive. Similar reference numerals in the drawings designatethe same or similar functions in many aspects.

A touch input device according to an embodiment of the present inventionwill be described with reference to the accompanying drawings. While acapacitance type touch sensor panel 100 and a pressure detection module400 are described below, the touch sensor panel 100 and the pressuredetection module 400 may be adopted, which are capable of detecting atouch position and/or touch pressure by any method.

FIG. 1 is a schematic view of a configuration of the capacitance touchsensor panel 100 and the operation thereof in accordance with theembodiment of the present invention. Referring to FIG. 1, the touchsensor panel 100 according to the embodiment of the present inventionmay include a plurality of drive electrodes TX1 to TXn and a pluralityof receiving electrodes RX1 to RXm, and may include a drive unit 120which applies a driving signal to the plurality of drive electrodes TX1to TXn for the purpose of the operation of the touch sensor panel 100,and a sensing unit 110 which detects the touch and the touch position byreceiving a sensing signal including information on the capacitancechange amount changing according to the touch on the touch surface ofthe touch sensor panel 100.

As shown in FIG. 1, the touch sensor panel 100 may include the pluralityof drive electrodes TX1 to TXn and the plurality of receiving electrodesRX1 to RXm. While FIG. 1 shows that the plurality of drive electrodesTX1 to TXn and the plurality of receiving electrodes RX1 to RXm of thetouch sensor panel 100 form an orthogonal array, the present inventionis not limited to this. The plurality of drive electrodes TX1 to TXn andthe plurality of receiving electrodes RX1 to RXm has an array ofarbitrary dimension, for example, a diagonal array, a concentric array,a 3-dimensional random array, etc., and an array obtained by theapplication of them. Here, “n” and “m” are positive integers and may bethe same as each other or may have different values. The magnitude ofthe value may be changed depending on the embodiment.

As shown in FIG. 1, the plurality of drive electrodes TX1 to TXn and theplurality of receiving electrodes RX1 to RXm may be arranged to crosseach other. The drive electrode TX may include the plurality of driveelectrodes TX1 to TXn extending in a first axial direction. Thereceiving electrode RX may include the plurality of receiving electrodesRX1 to RXm extending in a second axial direction crossing the firstaxial direction.

In the touch sensor panel 100 according to the embodiment of the presentinvention, the plurality of drive electrodes TX1 to TXn and theplurality of receiving electrodes RX1 to RXm may be formed in the samelayer. For example, the plurality of drive electrodes TX1 to TXn and theplurality of receiving electrodes RX1 to RXm may be formed on the sameside of an insulation layer (not shown). Also, the plurality of driveelectrodes TX1 to TXn and the plurality of receiving electrodes RX1 toRXm may be formed in the different layers. For example, the plurality ofdrive electrodes TX1 to TXn and the plurality of receiving electrodesRX1 to RXm may be formed on both sides of one insulation layer (notshown) respectively, or the plurality of drive electrodes TX1 to TXn maybe formed on a side of a first insulation layer (not shown) and theplurality of receiving electrodes RX1 to RXm may be formed on a side ofa second insulation layer (not shown) different from the firstinsulation layer.

The plurality of drive electrodes TX1 to TXn and the plurality ofreceiving electrodes RX1 to RXm may be made of a transparent conductivematerial (for example, indium tin oxide (ITO) or antimony tin oxide(ATO) which is made of tin oxide (SnO₂), and indium oxide (In₂O₃),etc.), or the like. However, this is only an example. The driveelectrode TX and the receiving electrode RX may be also made of anothertransparent conductive material or an opaque conductive material. Forinstance, the drive electrode TX and the receiving electrode RX may beformed to include at least any one of silver ink, copper or carbonnanotube (CNT). Also, the drive electrode TX and the receiving electrodeRX may be made of metal mesh or nano silver.

The drive unit 120 according to the embodiment of the present inventionmay apply a driving signal to the drive electrodes TX1 to TXn. In theembodiment of the present invention, one driving signal may besequentially applied at a time to the first drive electrode TX1 to then-th drive electrode TXn. The driving signal may be applied againrepeatedly. This is only an example. The driving signal may be appliedto the plurality of drive electrodes at the same time in accordance withthe embodiment.

Through the receiving electrodes RX1 to RXm, the sensing unit 110receives the sensing signal including information on a capacitance (Cm)101 generated between the receiving electrodes RX1 to RXm and the driveelectrodes TX1 to TXn to which the driving signal has been applied,thereby detecting whether or not the touch has occurred and where thetouch has occurred. For example, the sensing signal may be a coupledsignal of the driving signal applied to the drive electrode TX by thecapacitance (CM) 101 generated between the receiving electrode RX andthe drive electrode TX. As such, the process of sensing the drivingsignal applied from the first drive electrode TX1 to the n-th driveelectrode TXn through the receiving electrodes RX1 to RXm can bereferred to as a process of scanning the touch sensor panel 100.

For example, the sensing unit 110 may include a receiver (not shown)which is connected to each of the receiving electrodes RX1 to RXmthrough a switch. The switch becomes the on-state in a time intervalduring which the signal of the corresponding receiving electrode RX issensed, thereby allowing the receiver to sense the sensing signal fromthe receiving electrode RX. The receiver may include an amplifier (notshown) and a feedback capacitor coupled between the negative (−) inputterminal of the amplifier and the output terminal of the amplifier,i.e., coupled to a feedback path. Here, the positive (+) input terminalof the amplifier may be connected to the ground. Also, the receiver mayfurther include a reset switch which is connected in parallel with thefeedback capacitor. The reset switch may reset the conversion fromcurrent to voltage that is performed by the receiver. The negative inputterminal of the amplifier is connected to the corresponding receivingelectrode RX and receives and integrates a current signal includinginformation on the capacitance (CM) 101, and then converts theintegrated current signal into voltage. The sensing unit 110 may furtherinclude an analog to digital converter (ADC) (not shown) which convertsthe integrated data by the receiver into digital data. Later, thedigital data may be input to a processor (not shown) and processed toobtain information on the touch on the touch sensor panel 100. Thesensing unit 110 may include the ADC and processor as well as thereceiver.

A controller 130 may perform a function of controlling the operations ofthe drive unit 120 and the sensing unit 110. For example, the controller130 generates and transmits a drive control signal to the drive unit120, so that the driving signal can be applied to a predetermined driveelectrode TX1 at a predetermined time. Also, the controller 130generates and transmits the drive control signal to the sensing unit110, so that the sensing unit 110 may receive the sensing signal fromthe predetermined receiving electrode RX at a predetermined time andperform a predetermined function.

In FIG. 1, the drive unit 120 and the sensing unit 110 may constitute atouch detection device (not shown) capable of detecting whether thetouch has occurred on the touch sensor panel 100 according to theembodiment of the present invention or not and where the touch hasoccurred. The touch detection device according to the embodiment of thepresent invention may further include the controller 130. The touchdetection device according to the embodiment of the present inventionmay be integrated and implemented on a touch sensing integrated circuit(IC, see reference numeral 150 of FIG. 12) in a touch input device 1000including the touch sensor panel 100. The drive electrode TX and thereceiving electrode RX included in the touch sensor panel 100 may beconnected to the drive unit 120 and the sensing unit 110 included intouch sensing IC 150 through, for example, a conductive trace and/or aconductive pattern printed on a circuit board, or the like. The touchsensing IC 150 may be placed on a circuit board on which the conductivepattern has been printed, for example, a first printed circuit board(hereafter, referred to as a first PCB) indicated by a reference numeral160 of FIG. 12. According to the embodiment, the touch sensing IC 150may be mounted on a main board for operation of the touch input device1000.

As described above, a capacitance (C) with a predetermined value isgenerated at each crossing of the drive electrode TX and the receivingelectrode RX. When an object like a finger approaches close to the touchsensor panel 100, the value of the capacitance may be changed. In FIG.1, the capacitance may represent a mutual capacitance (Cm). The sensingunit 110 senses such electrical characteristics, thereby being able tosense whether the touch has occurred on the touch sensor panel 100 ornot and where the touch has occurred. For example, the sensing unit 110is able to sense whether the touch has occurred on the surface of thetouch sensor panel 100 comprised of a two-dimensional plane consistingof a first axis and a second axis.

More specifically, when the touch occurs on the touch sensor panel 100,the drive electrode TX to which the driving signal has been applied isdetected, so that the position of the second axial direction of thetouch can be detected. Likewise, when the touch occurs on the touchsensor panel 100, the capacitance change is detected from the receptionsignal received through the receiving electrode RX, so that the positionof the first axial direction of the touch can be detected.

The mutual capacitance type touch sensor panel as the touch sensor panel100 has been described in detail in the foregoing. However, in the touchinput device 1000 according to the embodiment of the present invention,the touch sensor panel 100 for detecting whether or not the touch hasoccurred and where the touch has occurred may be implemented by usingnot only the above-described method but also any touch sensing methodlike a magnetic capacitance type method, a surface capacitance typemethod, a projected capacitance type method, a resistance film method, asurface acoustic wave (SAW) method, an infrared method, an opticalimaging method, a dispersive signal technology, and an acoustic pulserecognition method, etc.

The touch sensor panel 100 for detecting where the touch has occurred inthe touch input device 1000 according to the embodiment of the presentinvention may be positioned outside or inside a display module 200.

The display module of the touch input device 1000 according to theembodiment of the present invention may be a display panel included in aliquid crystal display (LCD), a plasma display panel (PDP), an organiclight emitting diode (OLED), etc. Accordingly, a user may perform theinput operation by touching the touch surface while visually identifyingcontents displayed on the display panel. Here, the display module 200may include a control circuit which receives an input from anapplication processor (AP) or a central processing unit (CPU) on a mainboard for the operation of the touch input device 1000 and displays thecontents that the user wants on the display panel. The control circuitmay be mounted on a second printed circuit board (hereafter, referred toas a second PCB) (210) in FIGS. 11a to 13c . Here, the control circuitfor the operation of the display module 200 may include a display panelcontrol IC, a graphic controller IC, and a circuit required to operateother display panels 200.

FIGS. 2a, 2b and 2c are conceptual views showing a relative position ofthe touch sensor panel with respect to the display module in the touchinput device according to the embodiment of the present invention. WhileFIGS. 2a to 2c show an LCD panel as a display panel 200A included withinthe display module 200, this is just an example. Any display panel maybe applied to the touch input device 1000 according to the embodiment ofthe present invention.

In this specification, the reference numeral 200A may designate thedisplay panel included in the display module 200. As shown in FIG. 2,the LCD panel 200A may include a liquid crystal layer 250 including aliquid crystal cell, a first glass layer 261 and a second glass layer262 which are disposed on both sides of the liquid crystal layer 250 andinclude electrodes, a first polarizer layer 271 formed on a side of thefirst glass layer 261 in a direction facing the liquid crystal layer250, and a second polarizer layer 272 formed on a side of the secondglass layer 262 in the direction facing the liquid crystal layer 250. Itis clear to those skilled in the art that the LCD panel may furtherinclude other configurations for the purpose of performing thedisplaying function and may be transformed.

FIG. 2a shows that the touch sensor panel 100 of the touch input device1000 is disposed outside the display module 200. The touch surface ofthe touch input device 1000 may be the surface of the touch sensor panel100. In FIG. 2a , the top surface of the touch sensor panel 100 is ableto function as the touch surface. Also, according to the embodiment, thetouch surface of the touch input device 1000 may be the outer surface ofthe display module 200. In FIG. 2a , the bottom surface of the secondpolarizer layer 272 of the display module 200 is able to function as thetouch surface. Here, in order to protect the display module 200, thebottom surface of the display module 200 may be covered with a coverlayer (not shown) like glass.

FIGS. 2b and 2c show that the touch sensor panel 100 of the touch inputdevice 1000 is disposed inside the display panel 200A. Here, in FIG. 2b, the touch sensor panel 100 for detecting the touch position isdisposed between the first glass layer 261 and the first polarizer layer271. Here, the touch surface of the touch input device 1000 is the outersurface of the display module 200. The top surface or bottom surface ofthe display module 200 in FIG. 2b may be the touch surface. FIG. 2cshows that the touch sensor panel 100 for detecting the touch positionis included in the liquid crystal layer 250. Also, according to theembodiment, the touch sensor panel 100 may be implemented such that theelectrical devices for the operation of the display panel 200A are usedfor the touch sensing. Here, the touch surface of the touch input device1000 is the outer surface of the display module 200. The top surface orbottom surface of the display module 200 in FIG. 2c may be the touchsurface. In FIGS. 2b and 2c , the top surface or bottom surface of thedisplay module 200, which can be the touch surface, may be covered witha cover layer (not shown) like glass.

The foregoing has described whether the touch has occurred on the touchsensor panel 100 according to the embodiment of the present or not andwhere the touch has occurred. Further, through use of the touch sensorpanel 100 according to the embodiment of the present, it is possible todetect the magnitude of the touch pressure as well as whether the touchhas occurred or not and where the touch has occurred. Also, apart fromthe touch sensor panel 100, it is possible to detect the magnitude ofthe touch pressure by further including the pressure detection modulewhich detects the touch pressure.

FIG. 3 is a cross sectional view of the touch input device configured todetect the touch position and touch pressure in accordance with a firstembodiment of the present invention.

In the touch input device 1000 including the display module 200, thetouch sensor panel 100 and the pressure detection module 400 whichdetect the touch position may be attached on the front side of thedisplay module 200, As a result, the display screen of the displaymodule 200 can be protected and the touch detection sensitivity of thetouch sensor panel 100 can be improved.

Here, the pressure detection module 400 may be operated apart from thetouch sensor panel 100 which detects the touch position. For example,the pressure detection module 400 may be configured to detect only thetouch pressure independently of the touch sensor panel 100 which detectsthe touch position. Also, the pressure detection module 400 may beconfigured to be coupled to the touch sensor panel 100 which detects thetouch position and to detect the touch pressure. For example, at leastone of the drive electrode TX and the receiving electrode RX included inthe touch sensor panel 100 which detects the touch position may be usedto detect the touch pressure.

FIG. 3 shows that the pressure detection module 400 is coupled to thetouch sensor panel 100 and detects the touch pressure. In FIG. 3, thepressure detection module 400 includes a spacer layer 420 which leaves aspace between the touch sensor panel 100 and the display module 200. Thepressure detection module 400 may include a reference potential layerspaced from the touch sensor panel 100 by the spacer layer 420. Here,the display module 200 may function as the reference potential layer.

The reference potential layer may have any potential which causes thechange of the capacitance 101 generated between the drive electrode TXand the receiving electrode RX. For instance, the reference potentiallayer may be a ground layer having a ground potential. The referencepotential layer may be the ground layer of the display module 200. Here,the reference potential layer may have a parallel plane with thetwo-dimensional plane of the display module 200.

As shown in FIG. 3, the touch sensor panel 100 is disposed apart fromthe display module 200, i.e., the reference potential layer. Here,depending on a method for adhering the touch sensor panel 100 to thedisplay module 200, the spacer layer 420 may be implemented in the formof an air gap between the touch sensor panel 100 and the display module200. The spacer layer 420 may be made of an impact absorbing material inaccordance with the embodiment. The spacer layer 420 may be filled witha dielectric material in accordance with the embodiment.

Here, a double adhesive tape (DAT) 430 may be used to fix the touchsensor panel 100 and the display module 200. For example, the areas thetouch sensor panel 100 and the display module 200 are overlapped witheach other. The touch sensor panel 100 and the display module 200 areadhered to each other by adhering the edge portions of the touch sensorpanel 100 and the display module 200 through use of the DAT 430. Therest portions of the touch sensor panel 100 and the display module 200may be spaced apart from each other by a predetermined distance “d”.

In general, even when the touch surface is touched without bending thetouch sensor panel 100, the capacitance (Cm) 101 between the driveelectrode TX and the receiving electrode RX is changed. That is, whenthe touch occurs on the touch sensor panel 100, the mutual capacitance(Cm) 101 may become smaller than a base mutual capacitance. This isbecause, when the conductive object like a finger approaches close tothe touch sensor panel 100, the object functions as the ground GND, andthen a fringing capacitance of the mutual capacitance (Cm) 101 isabsorbed in the object. The base mutual capacitance is the value of themutual capacitance between the drive electrode TX and the receivingelectrode RX when there is no touch on the touch sensor panel 100.

When the object touches the top surface, i.e., the touch surface of thetouch sensor panel 100 and a pressure is applied to the top surface, thetouch sensor panel 100 may be bent. Here, the value of the mutualcapacitance (Cm) 101 between the drive electrode TX and the receivingelectrode RX may be more reduced. This is because the bend of the touchsensor panel 100 causes the distance between the touch sensor panel 100and the reference potential layer to be reduced from “d” to “d′”, sothat the fringing capacitance of the mutual capacitance (Cm) 101 isabsorbed in the reference potential layer as well as in the object. Whena nonconductive object touches, the change of the mutual capacitance(Cm) 101 is simply caused by only the change of the distance “d-d′”between the touch sensor panel 100 and the reference potential layer.

As described above, the touch input device 1000 is configured to includethe touch sensor panel 100 and the pressure detection module 400 on thedisplay module 200, so that not only the touch position but also thetouch pressure can be simultaneously detected.

However, as shown in FIG. 3, when the pressure detection module 400 aswell as the touch sensor panel 100 is disposed on the display module200, the display properties of the display module is deteriorated.Particularly, when the air gap 420 is included on the display module200, the visibility and optical transmittance of the display module maybe lowered.

Accordingly, in order to prevent such problems, the air gap is notdisposed between the display module 200 and the touch sensor panel 100for detecting the touch position. Instead, the touch sensor panel 100and the display module 200 can be completely laminated by means of anadhesive like an optically clear adhesive (OCA).

FIGS. 4a to 4f show a touch input device according to a secondembodiment of the present invention. In the touch input device 1000according to the second embodiment of the present invention, thelamination is made by an adhesive between the touch sensor panel 100 andthe display module 200 for detecting the touch position. As a result,the display color clarity, visibility and optical transmittance of thedisplay module 200, which can be recognized through the touch surface ofthe touch sensor panel 100, can be improved.

In the description with reference to FIGS. 4a to 4f , it is shown thatas the touch input device 1000 according to the second embodiment of thepresent invention, the touch sensor panel 100 is laminated and attachedon the display module 200 by means of an adhesive. However, the touchinput device 1000 according to the second embodiment of the presentinvention may include, as shown in FIGS. 2b and 2c , that the touchsensor panel 100 is disposed inside the display module 200. Morespecifically, while FIGS. 4a and 4b show that the touch sensor panel 100covers the display module 200, the touch input device 1000 whichincludes the touch sensor panel 100 disposed inside the display module200 and includes the display module 200 covered with a cover layer likeglass may be used as the second embodiment of the present invention.

The touch input device 1000 according to the embodiment of the presentinvention may include an electronic device including the touch screen,for example, a cell phone, a personal data assistant (PDA), a smartphone, a tablet personal computer, an MP3 player, a laptop computer,etc.

In the touch input device 1000 according to the embodiment of thepresent invention, a substrate 300, together with an outermost cover 320of the touch input device 1000, functions as, for example, a housingwhich surrounds a mounting space 310, etc., where the circuit boardand/or battery for operation of the touch input device 1000 are placed.Here, the circuit board for operation of the touch input device 1000 maybe a main board. A central processing unit (CPU), an applicationprocessor (AP) or the like may be mounted on the circuit board. Due tothe substrate 300, the display module 200 is separated from the circuitboard and/or battery for operation of the touch input device 1000. Dueto the substrate 300, electrical noise generated from the display module200 can be blocked.

The touch sensor panel 100 or front cover layer of the touch inputdevice 1000 may be formed wider than the display module 200, thesubstrate 300, and the mounting space 310. As a result, the cover 320 isformed such that the cover 320, together with the touch sensor panel100, surrounds the display module 200, the substrate 300, and themounting space 310.

The touch input device 1000 according to the second embodiment of thepresent may detect the touch position through the touch sensor panel 100and may detect the touch pressure by disposing the pressure detectionmodule 400 between the display module 200 and the substrate 300. Here,the touch sensor panel 100 may be disposed inside or outside the displaymodule 200. The pressure detection module 400 is formed to include, forexample, the spacer layer 420 consisting of the air gap. This will bedescribed in detail with reference to FIGS. 4b to 4f . The spacer layer420 may be made of an impact absorbing material in accordance with theembodiment. The spacer layer 420 may be filled with a dielectricmaterial in accordance with the embodiment.

FIG. 4b is a perspective view of the touch input device according to thesecond embodiment of the present invention. As shown in FIG. 4b , in thetouch input device 1000 according to the embodiment of the present, thepressure detection module 400 may include the spacer layer 420 whichleaves a space between the display module 200 and the substrate 300 andmay include electrodes 450 and 460 disposed within the spacer layer 420.Hereafter, for the purpose of clearly distinguishing the electrodes 450and 460 from the electrode included in the touch sensor panel 100, theelectrodes 450 and 460 for detecting the pressure are designated aspressure electrodes 450 and 460. Here, since the pressure electrodes 450and 460 are included in the rear side instead of in the front side ofthe display panel, the pressure electrodes 450 and 460 may be made of anopaque material as well as a transparent material.

Here, the adhesive tape 430 with a predetermined thickness may be formedalong the border of the upper portion of the substrate 300 in order tomaintain the spacer layer 420. While FIG. 4b shows the adhesive tape 430is formed on the entire border (e.g., four sides of the quadrangle) ofthe substrate 300, the adhesive tape 430 may be formed only on at leastsome (e.g., three sides of the quadrangle) of the border of thesubstrate 300. According to the embodiment, the adhesive tape 430 may beformed on the top surface of the substrate 300 or on the bottom surfaceof the display module 200. The adhesive tape 430 may be a conductivetape such that the substrate 300 and the display module 200 have thesame electric potential. The adhesive tape 430 may be a double adhesivetape. In the embodiment of the present invention, the adhesive tape 430may be made of an inelastic material. In the embodiment of the presentinvention, when a pressure is applied to the display module 200, thedisplay module 200 may be bent. Therefore, the magnitude of the touchpressure can be detected even though the adhesive tape 430 is nottransformed by the pressure.

FIG. 4c is a cross sectional view of the touch input device including apressure electrode pattern according to the embodiment of the presentinvention. As shown in FIG. 4c , the pressure electrodes 450 and 460according to the embodiment of the present invention may be formedwithin the spacer layer 420 and on the substrate 300.

The pressure electrode for detecting the pressure may include the firstelectrode 450 and the second electrode 460. Here, any one of the firstand the second electrodes 450 and 460 may be a drive electrode and theother may be a receiving electrode. A driving signal is applied to thedrive electrode, and a sensing signal may be obtained through thereceiving electrode. When voltage is applied, the mutual capacitance maybe generated between the first electrode 450 and the second electrode460.

FIG. 4d is a cross sectional view when a pressure is applied to thetouch input device 1000 shown in FIG. 4c . The bottom surface of thedisplay module 200 may have a ground potential so as to block the noise.When the pressure is applied to the surface of the touch sensor panel100 by an object 500, the touch sensor panel 100 and the display module200 may be bent or pressed. As a result, the distance “d” between theground potential surface and the pressure electrode patterns 450 and 460may be decreased to “d′”. In this case, due to the decrease of thedistance “d”, the fringing capacitance is absorbed in the bottom surfaceof the display module 200, so that the mutual capacitance between thefirst electrode 450 and the second electrode 460 may be reduced.Therefore, the magnitude of the touch pressure can be calculated byobtaining the reduction amount of the mutual capacitance from thesensing signal obtained through the receiving electrode.

In the touch input device 1000 according to the embodiment of thepresent invention, the display module 200 may be bent or pressed by thetouch pressure. The display module 200 may be bent or pressed in such amanner as to show the transformation caused by the touch. When thedisplay module 200 is bent or pressed according to the embodiment, aposition showing the biggest transformation may not match the touchposition. However, the display module 200 may be shown to be bent atleast at the touch position. For example, when the touch positionapproaches close to the border, edge, etc., of the display module 200,the most bent or pressed position of the display module 200 may notmatch the touch position, however, the display module 200 may be shownto be bent or pressed at least at the touch position.

Here, the top surface of the substrate 300 may also have the groundpotential in order to block the noise. Therefore, in order to prevent ashort-circuit from occurring between the substrate 300 and the pressureelectrodes 450 and 460, the pressure electrodes 450 and 460 may beformed on an insulation layer 470. FIG. 9 shows an attachment structureof the pressure electrode according the embodiment of the presentinvention. Referring to FIG. 9a , the first insulation layer 470 ispositioned on the substrate 300, and then the pressure electrodes 450and 460 are formed. Also, according to the embodiment, the firstinsulation layer 470 on which the pressure electrodes 450 and 460 havebeen formed may be attached on the substrate 300. Also, the pressureelectrode according to the embodiment may be formed by positioning amask, which has a through-hole corresponding to the pressure electrodepattern, on the substrate 300 or on the first insulation layer 470positioned on the substrate 300, and then by spraying a conductivematerial.

Also, when the bottom surface of the display module 200 has the groundpotential, the pressure electrodes 450 and 460 may be covered with anadditional second insulation layer 471 in order to prevent ashort-circuit from occurring between the display module 200 and thepressure electrode 450 and 460 positioned on the substrate 300. Also,the pressure electrodes 450 and 460 formed on the first insulation layer470 are covered with the additional second insulation layer 471 and thenare integrally attached on the substrate 300, so that the pressuredetection module 400 is formed.

The pressure electrode 450 and 460 attachment structure and method,which have been described with reference to FIG. 9a , may be applied tothe attachment of the pressure electrodes 450 and 460 to the displaymodule 200. The attachment of the pressure electrodes 450 and 460 to thedisplay module 200 will be described in more detail with reference toFIG. 4 e.

Also, depending on the kind and/or implementation method of the touchinput device 1000, the substrate 300 or the display module 200 on whichthe pressure electrodes 450 and 460 are attached may not have the groundpotential or may have a weak ground potential. In this case, the touchinput device 1000 according to the embodiment of the present may furtherinclude a ground electrode (not shown) between the first insulationlayer 470 and either the substrate 300 or the display module 200.According to the embodiment, another insulation layer (not shown) may beincluded between the ground electrode and either the substrate 300 orthe display module 200. Here, the ground electrode (not shown) is ableto prevent the size of the capacitance generated between the firstelectrode 450 and the second electrode 460, which are pressureelectrodes, from increasing excessively.

The above-described method for forming and attaching pressure electrode450 and 460 can be applied in the same manner to the followingembodiments.

FIG. 4e shows that the pressure electrodes 450 and 460 according to theembodiment of the present invention are formed on the bottom surface ofthe display module 200. Here, the substrate 300 may have the groundpotential. Therefore, the distance “d” between the substrate 300 and thepressure electrodes 450 and 460 is reduced by touching the touch surfaceof the touch sensor panel 100. Consequently, this may cause the changeof the mutual capacitance between the first electrode 450 and the secondelectrode 460.

FIGS. 7a to 7e show the pressure electrode patterns according to theembodiment of the present invention. FIGS. 7a to 7c show that the firstelectrode 450 and the second electrode 460 are formed on the substrate300 or on the bottom surface of the display module 200. The capacitancebetween the first electrode 450 and the second electrode 460 may bechanged depending on the distance between the reference potential layer(display module 200 or substrate 300) and both the first electrode 450and the second electrode 460.

When the magnitude of the touch pressure is detected as the mutualcapacitance between the first electrode 450 and the second electrode 460is changed, it is necessary to form the patterns of the first electrode450 and the second electrode 460 so as to generate the range of thecapacitance required to improve the detection accuracy. With theincrease of a facing area or facing length of the first electrode 450and the second electrode 460, the size of the capacitance that isgenerated may become larger. Therefore, the pattern can be designed byadjusting the size of the facing area, facing length and facing shape ofthe first electrode 450 and the second electrode 460 in accordance withthe range of the necessary capacitance. FIGS. 7b and 7c show that thefirst electrode 450 and the second electrode 460 are formed in the samelayer, and show that the pressure electrode is formed such that thefacing length of the first electrode 450 and the second electrode 460becomes relatively longer.

In the foregoing, it is shown that the first electrode 450 and thesecond electrode 460 are formed in the same layer. However, it can beconsidered that the first electrode 450 and the second electrode 460 areformed in different layers in accordance with the embodiment. FIG. 9bshows an attachment structure in which the first electrode 450 and thesecond electrode 460 are formed in different layers. As shown in FIG. 9b, the first electrode 450 may be formed on the first insulation layer470, and the second electrode 460 may be formed on the second insulationlayer 471 positioned on the first electrode 450. According to theembodiment, the second electrode 460 may be covered with a thirdinsulation layer 472. Here, since the first electrode 450 and the secondelectrode 460 are disposed in different layers, they can be implementedso as to overlap each other. For example, the first electrode 450 andthe second electrode 460 may be formed similarly to the pattern of thedrive electrode TX and receiving electrode RX which are arranged in theform of M×N array and are included in the touch sensor panel 100described with reference to FIG. 1. Here, M and N may be natural numbersgreater than 1.

In the foregoing, it is shown that the touch pressure is detected fromthe change of the mutual capacitance between the first electrode 450 andthe second electrode 460. However, the pressure electrodes 450 and 460may be configured to include only any one of the first electrode 450 andthe second electrode 460. In this case, it is possible to detect themagnitude of the touch pressure by detecting the change of thecapacitance between the one pressure electrode and the ground layer(either the display module 200 or the substrate 300).

For instance, in FIG. 4c , the pressure electrode may be configured toinclude only the first electrode 450. Here, the magnitude of the touchpressure can be detected by the change of the capacitance between thefirst electrode 450 and the display module 200, which is caused by thedistance change between the display module 200 and the first electrode450. Since the distance “d” is reduced with the increase of the touchpressure, the capacitance between the display module 200 and the firstelectrode 450 may be increased with the increase of the touch pressure.This can be applied in the same manner to the embodiment related to FIG.4e . Here, the pressure electrode should not necessary have a comb teethshape or a trident shape, which is required to improve the detectionaccuracy of the mutual capacitance change amount. The pressure electrodemay have, as shown in FIG. 7d , a plate shape (e.g., quadrangularplate).

FIG. 9c shows an attachment structure in which the pressure electrode isformed to include only the first electrode 450. As shown in FIG. 9c ,the first electrode 450 may be formed on the first insulation layer 470positioned on the substrate 300 or display module 200. Also, accordingto the embodiment, the first electrode 450 may be covered with thesecond insulation layer 471.

FIG. 4f shows that the pressure electrodes 450 and 460 are formed withinthe spacer layer 420 and on the top surface of the substrate 300 and onthe bottom surface of the display module 200. The pressure electrodepattern for detecting the pressure may include the first electrode 450and the second electrode 460. Here, any one of the first electrode 450and the second electrode 460 may be formed on the substrate 300, and theother may be formed on the bottom surface of the display module 200.FIG. 4f shows that the first electrode 450 is formed on the substrate300, and the second electrode 460 is formed on the bottom surface of thedisplay module 200.

When the pressure is applied to the surface of the touch sensor panel100 by the object 500, the touch sensor panel 100 and the display module200 may be bent or pressed. As a result, the distance “d” between thefirst electrode 450 and the second electrode 460 may be reduced. In thiscase, the mutual capacitance between the first electrode 450 and thesecond electrode 460 may be increased with the reduction of the distance“d”. Therefore, the magnitude of the touch pressure can be calculated byobtaining the increase amount of the mutual capacitance from the sensingsignal obtained through the receiving electrode. Here, the pressureelectrode patterns of the first electrode 450 and the second electrode460 may have a shape as shown in FIG. 7d respectively. That is, sincethe first electrode 450 and the second electrode 460 are formed indifferent layers in FIG. 4f , the first electrode 450 and the secondelectrode 460 should not necessarily have a comb teeth shape or atrident shape, and may have a plate shape (e.g., quadrangular plate).

FIG. 9d shows an attachment structure in which the first electrode 450is attached on the substrate 300 and the second electrode 460 isattached to the display module 200. As shown in FIG. 9d , the firstelectrode 450 may be positioned on the first insulation layer 470-2formed on the substrate 300 and may be covered with the secondinsulation layer 471-2. Also, the second electrode 460 may be positionedon the first insulation layer 470-1 formed on the bottom surface of thedisplay module 200 and may be covered with the second insulation layer471-1.

As with the description related to FIG. 9a , when substrate 300 or thedisplay module 200 on which the pressure electrodes 450 and 460 areattached may not have the ground potential or may have a weak groundpotential, a ground electrode (not shown) may be further includedbetween the first insulation layers 470, 470-1, and 470-2 in FIGS. 9a to9d . Here, an additional insulation layer (not shown) may be furtherincluded between the ground electrode (not shown) and either thesubstrate 300 or the display module 200 on which the pressure electrodes450 and 460 are attached.

FIGS. 5a to 5i show a touch input device according to a third embodimentof the present invention. The third embodiment of the present inventionis similar to the second embodiment described with reference to FIGS. 4ato 4f . Hereafter, the following description will focus on differencesbetween the second and third embodiments.

FIG. 5a is a cross sectional view of the touch input device according tothe third embodiment of the present invention.

In the touch input device 1000 according to the second embodiment of thepresent invention, the touch pressure can be detected by using the airgap and/or potential layer which are positioned inside or outside thedisplay module 200 without manufacturing a separate spacer layer and/orreference potential layer. This will be described in detail withreference to FIGS. 5b to 5 i.

FIG. 5b is an exemplary cross sectional view of the display module 200which can be included in the touch input device 1000 according to thethird embodiment of the present invention. FIG. 5b shows an LCD moduleas the display module 200. As shown in FIG. 5b , the LCD module 200 mayinclude an LCD panel 200A and a backlight unit 200B. The LCD panel 200Acannot emit light in itself but simply performs a function to block ortransmit the light. Therefore, a light source is positioned in the lowerportion of the LCD panel 200A and light is illuminated onto the LCDpanel 200A, so that a screen displays not only brightness and darknessbut information with various colors. Since the LCD panel 200A is apassive device and cannot emit the light in itself, a light sourcehaving a uniform luminance distribution is required on the rear side.The structures and functions of the LCD panel 200A and the backlightunit 200B have been already known to the public and will be brieflydescribed below.

The backlight unit 200B for the LCD panel 200A may include severaloptical parts. In FIG. 5b , the backlight unit 200B may include a lightdiffusing and light enhancing sheet 231, a light guide plate 232, and areflection plate 240. Here, the backlight unit 200B may include a lightsource (not shown) which is formed in the form of a linear light sourceor point light source and is disposed on the rear and/or side of thelight guide plate 232. According to the embodiment, a support 233 may befurther included on the edges of the light guide plate 232 and the lightdiffusing and light enhancing sheet 231.

The light guide plate 232 may generally convert lights from the lightsource (not shown) in the form of a linear light source or point lightsource into light from a light source in the form of a surface lightsource, and allow the light to proceed to the LCD panel 200A.

A part of the light emitted from the light guide plate 232 may beemitted to a side opposite to the LCD panel 200A and be lost. Thereflection plate 240 may be positioned below the light guide plate 232so as to cause the lost light to be incident again on the light guideplate 232, and may be made of a material having a high reflectance.

The light diffusing and light enhancing sheet 231 may include a diffusersheet and/or a prism sheet. The diffuser sheet functions to diffuse thelight incident from the light guide plate 232. For example, lightscattered by the pattern of the light guide plate 232 comes directlyinto the eyes of the user, and thus, the pattern of the light guideplate 232 may be shown as it is. Moreover, since such a pattern can beclearly sensed even after the LCD panel 200A is mounted, the diffusersheet is able to perform a function to scatter the pattern of the lightguide plate 232.

After the light passes through the diffuser sheet, the luminance of thelight is rapidly reduced. Therefore, the prism sheet may be included inorder to improve the luminance of the light by focusing the light again.

The backlight unit 200B may include a configuration different from theabove-described configuration in accordance with the technical changeand development and/or the embodiment. The backlight unit 200B mayfurther include an additional configuration as well as the foregoingconfiguration. Also, in order to protect the optical configuration ofthe backlight unit 200B from external impacts and contamination, etc.,due to the introduction of the alien substance, the backlight unit 200Baccording to the embodiment of the present may further include, forexample, a protection sheet on the prism sheet. The backlight unit 200Bmay also further include a lamp cover in accordance with the embodimentso as to minimize the optical loss of the light source. The backlightunit 200B may also further include a frame which maintains a shapeenabling the light diffusing and light enhancing sheet 231, the lightguide plate 232, a lamp (not shown), and the like, which are maincomponents of the backlight unit 200B, to be exactly dissembled andassembled together in accordance with an allowed dimension. Also, theeach of the components may be comprised of at least two separate parts.For example, the prism sheet may include two prism sheets.

Here, a first air gap 220-2 may be positioned between the light guideplate 232 and the reflection plate 240. As a result, the lost light fromthe light guide plate 232 to the reflection plate 240 can be incidentagain on the light guide plate 232 by the reflection plate 240. Here,between the light guide plate 232 and the reflection plate 240, for thepurpose of maintaining the air gap 220-2, a double adhesive tape 221-2may be included on the edges of the light guide plate 232 and thereflection plate 240.

Also, according to the embodiment, the backlight unit 200B and the LCDpanel 200A may be positioned with the second air gap 220-1 placedtherebetween. This intends to prevent that the impact from the LCD panel200A is transmitted to the backlight unit 200B. Here, between thebacklight unit 200B and the LCD panel 200A, a double adhesive tape 221-1may be included on the edges of the LCD panel 200A and the backlightunit 200B.

As described above, the display module 200 may be configured to includein itself the air gap such as the first air gap 220-2 and/or the secondair gap 220-1. Also, the air gap may be included between a plurality ofthe layers of the light diffusing and light enhancing sheet 231. In theforegoing, while the LCD module has been described, the air gap may beincluded within the structure of another display module.

Therefore, for detecting the touch pressure, the touch input device 1000according to the third embodiment of the present invention may make useof the air gap which has been already positioned inside or outside thedisplay module 200 without manufacturing a separate spacer layer. Theair gap which is used as the spacer layer may be not only the first airgap 220-2 and/or the second air gap 220-1 which are described withreference to FIG. 5b but also any air gap included inside the displaymodule 200. Also, the air gap which is used as the spacer layer may bean air gap included outside the display module 200. As such, themanufacture of the touch input device 1000 capable of detecting thetouch pressure reduces manufacturing cost and/or simplifies themanufacturing process. FIG. 5c is a perspective view of the touch inputdevice according to the third embodiment of the present invention. InFIG. 5c , unlike the second embodiment shown in FIG. 4b , the doubleadhesive tape 430 for maintaining the spacer layer 420 may not beincluded.

FIG. 5d is a cross sectional view of the touch input device according tothe third embodiment. As shown in FIG. 5d , between the display module200 and the substrate 300, the pressure electrodes 450 and 460 may beformed on the substrate 300. In FIGS. 5d to 5i , the pressure electrodes450 and 460 are shown exaggeratedly thick for convenience ofdescription. However, since the pressure electrodes 450 and 460 can beimplemented in the form of a sheet, the thickness of the first electrode450 and the second electrode 460 may be very small. Likewise, althoughthe distance between the display module 200 and the substrate 300 isalso shown exaggeratedly large, the display module 200 and the substrate300 may be implemented to have a very small distance therebetween. FIGS.5d and 5e show that the display module 200 and the pressure electrodes450 and 460 are spaced apart from each other so as to represent that thefirst electrode 450 and the second electrode 460 have been formed on thesubstrate 300. However, this is for description only. The display module200 and the first and second electrodes 450 and 460 may not be spacedapart from each other.

Here, FIG. 5d shows that the display module 200 includes a spacer layer220 and a reference potential layer 270.

The spacer layer 220 may be, as described with reference to FIG. 5b ,the first air gap 220-2 and/or the second air gap 220-1 which areincluded during the manufacture of the display module 200. When thedisplay module 200 includes one air gap, the air gap may function as thespacer layer 220. When the display module 200 includes a plurality ofair gaps, the plurality of air gaps may collectively function as thespacer layer 220. FIGS. 5d, 5e, 5h and 5i show that the display module200 functionally includes one spacer layer 220.

According to the embodiment of the present invention, the touch inputdevice 1000 may include the reference potential layer 270 which ispositioned above the spacer layer 220 within the display panel 200A ofFIGS. 2a to 2c . The reference potential layer 270 may be a groundpotential layer which is included in itself during the manufacture ofthe display module 200. For example, in the display panel 200A shown inFIGS. 2a to 2c , an electrode (not shown) for blocking the noise may beincluded between the first polarizer layer 271 and the first glass layer261. The electrode for blocking the noise may be composed of ITO and mayfunction as the ground. Within the display module 200, the referencepotential layer 270 may be located at any position causing the spacerlayer 220 to be placed between the reference potential layer 270 and thepressure electrodes 450 and 460. Not only the above-described blockingelectrode but also an electrode having any potential may be used as thereference potential layer 270. For example, the reference potentiallayer 270 may be a common electrode potential (Vcom) layer of thedisplay module 200.

Particularly, as part of an effort to reduce the thickness of the deviceincluding the touch input device 1000, the display module 200 may not besurrounded by a separate cover or frame. In this case, the bottomsurface of the display module 200, which faces the substrate 300, may bethe reflection plate 240 and/or a nonconductor. In this case, the bottomsurface of the display module 200 cannot have the ground potential. Asmentioned, even when the bottom surface of the display module 200 cannotfunction as the reference potential layer, it is possible to detect thetouch pressure by using any potential layer positioned within thedisplay module 200 as the reference potential layer 270 through use ofthe touch input device 1000 according to the embodiment of the presentinvention.

FIG. 5e is a cross sectional view of a case where a pressure has beenapplied to the touch input device 1000 shown in FIG. 5d . When thepressure is applied to the surface of the touch sensor panel 100 by theobject 500, the touch sensor panel 100 or the display module 200 may bebent or pressed. Here, the distance “d” between the reference potentiallayer 270 and the pressure electrode patterns 450 and 460 may bedecreased to “d′” by the spacer layer 220 positioned within the displaymodule 200. In this case, due to the decrease of the distance “d”, thefringing capacitance is absorbed in the reference potential layer 270,so that the mutual capacitance between the first electrode 450 and thesecond electrode 460 may be reduced. Therefore, the magnitude of thetouch pressure can be calculated by obtaining the reduction amount ofthe mutual capacitance from the sensing signal obtained through thereceiving electrode.

In the touch sensor panel 100 according to the embodiment of the presentinvention, the display module 200 may be bent or pressed by the touchpressure. Here, as shown in FIG. 5e , due to the spacer layer 220, thelayer positioned below the spacer layer 220 (e.g., the reflection plate)may not be bent or pressed or may be less bent or pressed. While FIG. 5eshows that the lowest portion of the display module 200 is not bent orpressed at all, this is just an example. The lowest portion of thedisplay module 200 may be bent or pressed. However, the degree to whichthe lowest portion of the display module 200 is bent or pressed can bereduced by the spacer layer 220.

Since the attachment structure of the pressure electrode according tothe third embodiment is the same as that described with reference to thesecond embodiment, the description thereof will be omitted.

FIG. 5f is a cross sectional view of the touch input device includingthe pressure electrode pattern according to the modification of theembodiment described with reference to FIG. 5d . FIG. 5f shows that thespacer layer 220 is positioned between the display module 200 and thesubstrate 300. When the touch input device 1000 including the displaymodule 200 is manufactured, the display module 200 is not completelyattached to the substrate 300, so that the air gap 420 may be created.Here, by using the air gap 420 as the spacer layer for detecting thetouch pressure, it is possible to reduce the time and cost intentionallyrequired for manufacturing the spacer layer for detecting the touchpressure. FIGS. 5f and 5g show that the air gap 420 used as the spacerlayer is not positioned within the display module 200. However, FIGS. 5fand 5g may additionally include a case where the air gap 420 ispositioned within the display module 200.

FIG. 5g is a cross sectional view of a case where a pressure has beenapplied to the touch input device shown in FIG. 5f . As with FIG. 5d ,when the touch occurs on the touch input device 1000, the display module200 may be bent or pressed. Here, the “d” between the referencepotential layer 270 and the pressure electrode patterns 450 and 460 maybe decreased to “d′” by the spacer layer 420 and/or the air gap 220which are positioned between the reference potential layer 270 and thepressure electrodes 450 and 460. As a result, the magnitude of the touchpressure can be calculated by obtaining the reduction amount of themutual capacitance from the sensing signal obtained through thereceiving electrode.

FIG. 5h shows that the pressure electrodes 450 and 460 are formed on thebottom surface of the display module 200. The distance “d” between thereference potential layer 270 and the pressure electrodes 450 and 460 isreduced by touching the touch surface of the touch sensor panel 100.Consequently, this may cause the change of the mutual capacitancebetween the first electrode 450 and the second electrode 460. FIG. 5hshows that the substrate 300 and the pressure electrodes 450 and 460 arespaced apart from each other so as to describe that the pressureelectrodes 450 and 460 are attached on the display module 200. However,this is for description only. The substrate 300 and the pressureelectrodes 450 and 460 may not be spaced apart from each other. Also, aswith FIGS. 5f and 5g , the display module 200 and the substrate 300 maybe spaced apart from each other by the spacer layer 420.

Similarly to the second embodiment, the pressure electrodes 450 and 460described with reference to FIGS. 5d to 5h according to the thirdembodiment may also have the pattern shown in FIGS. 7a to 7c , andrepetitive descriptions thereof will be omitted.

FIG. 5i shows that the pressure electrodes 450 and 460 are formed on thetop surface of the substrate 300 and on the bottom surface of thedisplay module 200. FIG. 5i shows that the first electrode 450 is formedon the substrate 300, and the second electrode 460 is formed on thebottom surface of the display module 200. FIG. 5i shows that the firstelectrode 450 is spaced apart from the second electrode 460. However,this is just intended to describe that the first electrode 450 is formedon the substrate 300 and the second electrode 460 is formed on thedisplay module 200. The first electrode 450 and the second electrode 460may be spaced apart from each other by the air gap, may have aninsulating material placed therebetween, or may be formed to deviatefrom each other, for example, may be formed in the same layer, not to beoverlapped with each other.

When the pressure is applied to the surface of the touch sensor panel100 by the object 500, the touch sensor panel 100 and the display module200 may be bent or pressed. As a result, the distance “d” between thepressure electrodes 450 and 460 and the reference potential layer 270may be reduced. In this case, the mutual capacitance between the firstelectrode 450 and the second electrode 460 may be reduced with thereduction of the distance “d”. Therefore, the magnitude of the touchpressure can be calculated by obtaining the reduction amount of themutual capacitance from the sensing signal obtained through thereceiving electrode. Here, the first electrode 450 and the secondelectrode 460 may have the pressure electrode pattern shown in FIG. 7e .FIG. 7e shows that the first electrode 450 is formed on the top surfaceof the substrate 300 and the second electrode 460 is formed on thebottom surface of the display module 200. As shown in FIG. 7e , thefirst electrode 450 and the second electrode 460 are disposedperpendicular to each other, so that the capacitance change amountdetection sensitivity can be enhanced.

FIGS. 6a to 6i show a touch input device according to a fourthembodiment of the present invention. The fourth embodiment is similar tothe second embodiment. Therefore, the following description will focuson the difference between the two embodiments.

FIG. 6a is a cross sectional view of the touch input device according tothe fourth embodiment of the present invention. In the fourthembodiment, the electrodes 450 and 460 included in the pressuredetection module 400 may be included in the touch input device 1000 inthe form of an electrode sheet 440 including the correspondingelectrode. Hereafter, this will be described in detail. Here, since theelectrodes 450 and 460 should be configured to include the air gap 420between the substrate 300 and the display module 200, FIG. 6a shows thatthe electrode sheet 440 including the electrodes 450 and 460 is disposedapart from the substrate 300 and the display module 200. However, theelectrodes 450 and 460 may be formed to contact any one of the substrate300 and the display module 200.

FIG. 6a is an exemplary cross sectional view of the electrode sheetincluding the pressure electrode to be attached to the touch inputdevice according to the fourth embodiment of the present invention. Forinstance, the electrode sheet 440 may include an electrode layer 441between the first insulation layer 470 and the second insulation layer471. The electrode layer 441 may include the first electrode 450 and/orthe second electrode 460. Here, the first insulation layer 470 and thesecond insulation layer 471 may be made of an insulating material likepolyimide. The first electrode 450 and/or the second electrode 460included in the electrode layer 441 may include a material like copper.In accordance with the manufacturing process of the electrode sheet 440,the electrode layer 441 and the second insulation layer 471 may beadhered to each other by means of an adhesive (not shown) like anoptically clear adhesive (OCA). Also, the pressure electrodes 450 and460 according to the embodiment may be formed by positioning a mask,which has a through-hole corresponding to the pressure electrodepattern, on the first insulation layer 470, and then by spraying aconductive material. FIG. 6b and the following description show that theelectrode sheet 440 has a structure in which the pressure electrodes 450and 460 are included between the insulation layers 470 and 471. However,this is only an example. The electrode sheet 440 may simply include onlythe pressure electrodes 450 and 460.

In the touch input device 1000 according to the fourth embodiment of thepresent invention, for the purpose of detecting the touch pressure, theelectrode sheet 440 may be attached to the display module 200 such thatthe electrode sheet 440 and either the substrate 300 or the displaymodule 200 are spaced apart from each other with the spacer layer 420placed therebetween.

FIG. 6c is a partial cross sectional view of the touch input deviceincluding the electrode sheet 440 attached thereto according to a firstmethod. FIG. 6c shows that the electrode sheet 440 has been attached onthe substrate 300 or the display module 200.

As shown in FIG. 6d , the adhesive tape 430 with a predeterminedthickness may be formed along the border of the electrode sheet 440 inorder to maintain the spacer layer 420. While FIG. 6d shows the adhesivetape 430 is formed on the entire border (e.g., four sides of thequadrangle) of the electrode sheet 440, the adhesive tape 430 may beformed only on at least some (e.g., three sides of the quadrangle) ofthe border of the electrode sheet 440. Here, as shown in FIG. 6d , theadhesive tape 430 may not formed in an area including the pressureelectrode patterns 450 and 460. As a result, when the electrode sheet440 is attached to the substrate 300 of the display module 200 by theadhesive tape 430, the pressure electrodes 450 and 460 may be spacedapart from the substrate 300 of the display module 200 by apredetermined distance. According to the embodiment, the adhesive tape430 may be formed on the top surface of the substrate 300 or on thebottom surface of the display module 200. Also, the adhesive tape 430may be a double adhesive tape. FIG. 6d shows only one out of thepressure electrodes 450 and 460.

FIG. 6e is a partial cross sectional view of the touch input deviceincluding the electrode sheet attached thereto according to a secondmethod. In FIG. 6e , after the electrode sheet 440 is positioned on thesubstrate 300 or the display module 200, the electrode sheet 440 can befixed to the substrate 300 or the display module 200 by means of anadhesive tape 431. For this, the adhesive tape 431 may contact at leasta portion of the electrode sheet 440 and at least a portion of thesubstrate 300 or the display module 200. FIG. 6e shows that the adhesivetape 431 continues from the top of the electrode sheet 440 to theexposed surface of the substrate 300 or the display module 200. Here,the surface of the adhesive tape 431, the surface contacting theelectrode sheet 440, may have an adhesive strength. Accordingly, in FIG.6e , the top surface of the adhesive tape 431 may have no adhesivestrength.

As shown in FIG. 6e , even though the electrode sheet 440 is fixed tothe substrate 300 or the display module 200 by the adhesive tape 431, apredetermined space, i.e., the air gap may be created between theelectrode sheet 440 and either the substrate 300 or the display module200. This is because the electrode sheet 440 is not directly attached toeither the substrate 300 or the display module 200 and because theelectrode sheet 440 includes the pressure electrodes 450 and 460 havinga pattern, so that the surface of the electrode sheet 440 may not beflat. The air gap 420 of FIG. 6e may also function as the spacer layer420 for detecting the touch pressure.

In the following description, the fourth embodiment has taken an exampleof a case where the electrode sheet 440 is attached t to the substrate300 or the display module 200 by the first method shown in FIG. 6c .However, the description can be applied to a case where the electrodesheet 440 is attached and spaced from the substrate 300 or the displaymodule 200 by any method like the second method, etc.

FIG. 6f is a cross sectional view of the touch input device includingthe pressure electrode pattern according to the fourth embodiment of thepresent invention. As shown in FIG. 6f , the electrode sheet 440including the pressure electrodes 450 and 460 may be attached to thesubstrate 300 such that particularly, the area where the pressureelectrodes 450 and 460 have been formed is spaced apart from thesubstrate 300 by the spacer layer 420. While FIG. 6f shows that thedisplay module 200 contacts the electrode sheet 440, this is just anexample. The display module 200 may be positioned apart from theelectrode sheet 440.

FIG. 6g is a cross sectional view of a case where a pressure has beenapplied to the touch input device 1000 shown in FIG. 6f . The substrate300 may have a ground potential so as to block the noise. When thepressure is applied to the surface of the touch sensor panel 100 by theobject 500, the touch sensor panel 100 and the display module 200 may bebent or pressed. As a result, the electrode sheet 440 is pressed, sothat the distance “d” between the substrate 300 and the pressureelectrodes 450 and 460 included in the electrode sheet 440 may bedecreased to “d′”. In this case, due to the decrease of the distance“d”, the fringing capacitance is absorbed in the substrate 300, so thatthe mutual capacitance between the first electrode 450 and the secondelectrode 460 may be reduced. Therefore, the magnitude of the touchpressure can be calculated by obtaining the reduction amount of themutual capacitance from the sensing signal obtained through thereceiving electrode.

As shown in FIGS. 6f and 6g , the touch input device 1000 according tothe fourth embodiment of the present invention is able to detect thetouch pressure by the distance change between the electrode sheet 440and the substrate 300 to which the electrode sheet 440 has beenattached. Here, since the distance “d” between the electrode sheet 440and the substrate 300 is very small, the touch input device 1000 is ableto precisely detect the touch pressure even by the minute change in thedistance “d” due to the touch pressure.

FIG. 6h shows that the pressure electrodes 450 and 460 are attached tothe bottom surface of the display module 200. FIG. 6i is a crosssectional view of a case where a pressure has been applied to the touchinput device shown in FIG. 6h . Here, the display module 200 may havethe ground potential. Therefore, the distance “d” between the displaymodule 200 and the pressure electrodes 450 and 460 is reduced bytouching the touch surface of the touch sensor panel 100. Consequently,this may cause the change of the mutual capacitance between the firstelectrode 450 and the second electrode 460.

As shown in FIGS. 6h and 6i , it can be understood that the touch inputdevice 1000 according to the fourth embodiment of the present inventioncan also detect the touch pressure by the distance change between theelectrode sheet 440 and the display module 200 to which the electrodesheet 440 has been attached.

For example, the distance between the display module 200 and theelectrode sheet 440 may be less than the distance between the electrodesheet 440 and the substrate 300. Also, for example, the distance betweenthe electrode sheet 440 and the bottom surface of the display module 200having the ground potential may be less than the distance between theelectrode sheet 440 and the Vcom potential layer and/or any groundpotential layer. For example, in the display panel 200 shown in FIGS. 2ato 2c , an electrode (not shown) for blocking the noise may be includedbetween the first polarizer layer 271 and the first glass layer 261. Theelectrode for blocking the noise may be composed of ITO and may functionas the ground.

The first electrode 450 and the second electrode 460 which are includedin FIGS. 6f to 6i may have the pattern shown in FIGS. 7a to 7c , andrepetitive descriptions thereof will be omitted.

In FIGS. 6a to 6i , it is shown that the first electrode 450 and thesecond electrode 460 are formed in the same layer. However, it can beconsidered that the first electrode 450 and the second electrode 460 areformed in different layers in accordance with the embodiment. As shownin FIG. 9b , in the electrode sheet 440, the first electrode 450 may beformed on the first insulation layer 470, and the second electrode 460may be formed on the second insulation layer 471 positioned on the firstelectrode 450. The second electrode 460 may be covered with the thirdinsulation layer 472.

Also, according to the embodiment, the pressure electrodes 450 and 460may be configured to include only any one of the first electrode 450 andthe second electrode 460. In this case, it is possible to detect themagnitude of the touch pressure by detecting the change of thecapacitance between the one pressure electrode and the ground layer(either the display module 200 or the substrate 300). Here, the pressureelectrode may have, as shown in FIG. 7d , a plate shape (e.g.,quadrangular plate). Here, as shown in FIG. 9 c, in the electrode sheet440, the first electrode 450 may be formed on the first insulation layer470 and may be covered with the third insulation layer 472.

FIGS. 8a and 8b show a relation between the magnitude of the touchpressure and a saturated area in the touch input device according to theembodiment of the present invention. Although FIGS. 8a and 8b show thatthe electrode sheet 440 is attached to the substrate 300, the followingdescription can be applied in the same manner to a case where theelectrode sheet 440 is attached to the display module 200.

The touch pressure with a sufficient magnitude makes a state where thedistance between the electrode sheet 440 and the substrate 300 cannot bereduced any more at a predetermined position. Hereafter, the state isdesignated as a saturation state. For instance, as shown in FIG. 8a ,when the touch input device 1000 is pressed by a force “f”, theelectrode sheet 440 contacts the substrate 300, and thus, the distancebetween the electrode sheet 440 and the substrate 300 cannot be reducedany more. Here, as shown on the right of FIG. 8a , the contact areabetween the electrode sheet 440 and the substrate 300 may be indicatedby “a”.

However, in this case, when the magnitude of the touch pressure becomeslarger, the contact area between the electrode sheet 440 and thesubstrate 300 in the saturation state where the distance between theelectrode sheet 440 and the substrate 300 cannot be reduced any more maybecome greater. For example, as shown in FIG. 8b , when the touch inputdevice 1000 is pressed by a force “F” greater than the force “f”, thecontact area between the electrode sheet 440 and the substrate 300 maybecome greater. As shown on the right of FIG. 8a , the contact areabetween the electrode sheet 440 and the substrate 300 may be indicatedby “A”. As such, the greater the contact area, the more the mutualcapacitance between the first electrode 450 and the second electrode 460may be reduced. Hereafter, it will be described that the magnitude ofthe touch pressure is calculated by the change of the capacitanceaccording to the distance change. This may include that the magnitude ofthe touch pressure is calculated by the change of the saturation area inthe saturation state.

FIGS. 8a and 8b are described with reference to the fourth embodiment.It is apparent that the description with reference to FIGS. 8a and 8bcan be applied in the same manner to the first to third embodiments andthe following fifth embodiment. More specifically, the magnitude of thetouch pressure can be calculated by the change of the saturation area inthe saturation state where the distance between the pressure electrodes450 and 460 and either the ground layer or the reference potential layer200, 300, and 270 cannot be reduced any more.

FIGS. 10a and 10b show a touch input device according to a fifthembodiment of the present invention. The touch input device 1000according to the fifth embodiment of the present invention can sense thetouch pressure even when the pressure is applied to the bottom surfaceas well as the top surface of the touch input device. In thisspecification, the top surface of the touch input device 1000 as thetouch surface may be designated as the top surface of the display module200 and may include not only the top surface of the display module 200but also the surface of a member covering the top surface of the displaymodule 200. Also, in this specification, the bottom surface of the touchinput device 1000 as the touch surface may be designated as the bottomsurface of the substrate 300 and may include not only the bottom surfaceof the substrate 300 but also the surface of a member covering thebottom surface of the substrate 300.

FIG. 10a shows that the pressure electrodes 450 and 460 are positionedon the bottom surface of the display module 200 in the secondembodiment. FIG. 10a shows that the distance between the substrate 300and the pressure electrodes 450 and 460 is changed when the substrate300 is pressed or bent by applying a pressure to the bottom surface ofthe substrate 300. Here, as the distance between the pressure electrodes450 and 460 and the substrate 300, i.e., the reference potential layeris changed, the capacitance between the first electrode 450 and thesecond electrode 460 or the capacitance between the substrate 300 andeither the first electrode 450 or the second electrode 460 is changed.Accordingly, the touch pressure can be detected.

FIG. 10b shows that the electrode sheet 440 is attached to the substrate300 in the third embodiment. FIG. 10b shows that the distance betweenthe substrate 300 and the electrode sheet 440 is changed when thesubstrate 300 is pressed or bent by applying a pressure to the bottomsurface of the substrate 300. As with the case of FIG. 10a , as thedistance between the pressure electrodes 450 and 460 and the substrate300, i.e., the reference potential layer is changed, the capacitancebetween the first electrode 450 and the second electrode 460 or thecapacitance between the substrate 300 and either the first electrode 450or the second electrode 460 is changed. Accordingly, the touch pressurecan be detected.

In FIGS. 10a and 10b , while the fifth embodiment has been describedbased on the structures of some examples of the second and thirdembodiments, the fifth embodiment can be applied to a case where thesubstrate 300 is bent or pressed by applying a pressure to the bottomsurface of the substrate 300 included in the structures of the first tofourth embodiments, so that the capacitance between the first electrode450 and the second electrode 460 is changed or the capacitance betweenthe first electrode 450 and the reference potential layer 200, 300, and270 is changed. For example, in the structure shown in FIG. 4c , whenthe substrate 300 is bent or pressed, the distance between the displaymodule 200 and the pressure electrodes 450 and 460 may be changed,thereby detecting the touch pressure.

As described above, the touch input device 1000 according to theembodiment of the present invention senses the capacitance changeoccurring in the pressure electrodes 450 and 460. Therefore, it isnecessary for the driving signal to be applied to the drive electrodeout of the first and second electrodes 450 and 460, and it is requiredto detect the touch pressure by the capacitance change amount byobtaining the sensing signal from the receiving electrode. According tothe embodiment, it is possible to additionally include a touch sensingIC for the operation of the pressure detection. In this case, the touchinput device repeatedly has a configuration similar to the configurationof FIG. 1 including the drive unit 120, sensing unit 110, and controller130, so that the area and volume of the touch input device 1000increase.

According to the embodiment, in the touch detection device 1000, thedriving signal for the operation of the touch sensor panel 100 isapplied and the sensing signal is received through the touch detectiondevice, so that the touch pressure can be detected. Hereafter, thefollowing description will be provided by assuming that the firstelectrode 450 is the drive electrode and the second electrode 460 is thereceiving electrode.

For this, in the touch input device 1000 according to the embodiment ofthe present invention, the driving signal may be applied to the firstelectrode 450 from the drive unit 120, and the second electrode 460 maytransmit the sensing signal to the sensing unit 110. The controller 130may perform the scanning of the touch sensor panel 100, andsimultaneously perform the scanning of the touch pressure detection, orthe controller 130 performs the time-sharing, and then may generate acontrol signal such that the scanning of the touch sensor panel 100 isperformed in a first time interval and the scanning of the pressuredetection is performed in a second time interval different from thefirst time interval.

Therefore, in the embodiment of the present invention, the firstelectrode 450 and the second electrode 460 should be electricallyconnected to the drive unit 120 and/or the sensing unit 110. Here, it iscommon that the touch detection device for the touch sensor panel 100corresponds to the touch sensing IC 150 and is formed on one end of thetouch sensor panel 100 or on the same plane with the touch sensor panel100. The pressure electrode patterns 450 and 460 may be electricallyconnected to the touch detection device of the touch sensor panel 100 byany method. For example, the pressure electrode patterns 450 and 460 maybe connected to the touch detection device through a connector by usingthe second PCB 210 included in the display module 200. For example, asshown in FIGS. 4b and 5c , the conductive traces 460 which electricallyextend from the first electrode 450 and the second electrode 460respectively may be electrically connected to the touch sensing IC 150through the second PCB 210, etc.

FIGS. 11a to 11b show that the pressure electrodes 450 and 460 (orelectrode sheet 440) are attached to the bottom surface of the displaymodule 200. FIGS. 11a and 11b show the second PCB 210 on which a circuitfor the operation of the display panel has been mounted is disposed on aportion of the bottom surface of the display module 200.

FIG. 11a shows that the pressure electrodes 450 and 460 are attached tothe bottom surface of the display module 200 such that the firstelectrode 450 and the second electrode 460 are connected to one end ofthe second PCB 210 of the display module 200. Here, FIG. 11a shows thatthe first electrode 450 and the second electrode 460 are manufactured onthe insulation layer 470. The first electrode 450 and the secondelectrode 460 is formed on the insulation layer 470 and may be attachedas an integral sheet on the bottom surface of the display module 200. Aconductive pattern may be printed on the second PCB 210 in such a manneras to electrically connect the pressure electrodes 450 and 460 to anecessary component like the touch sensing IC 150, etc. The detaileddescription of this will be provided with reference to FIGS. 12a to 12c. An attachment method of the pressure electrodes 450 and 460 can beapplied in the same manner to the substrate 300.

FIG. 11b shows that the pressure electrodes 450 and 460 are integrallyformed on the second PCB 210 of the display module 200. For example,when the second PCB 210 of the display module 200 is manufactured, acertain area 211 is spared from the second PCB, and then not only thecircuit for the operation of the display panel but also the patterncorresponding to the first electrode 450 and the second electrode 460can be printed on the area 211. A conductive pattern may be printed onthe second PCB 210 in such a manner as to electrically connect the firstelectrode 450 and the second electrode 460 to a necessary component likethe touch sensing IC 150, etc.

FIGS. 12a to 12c show a method for connecting the pressure electrodes450 and 460 (or electrode sheet 440) to the touch sensing IC 150. InFIGS. 12a to 12c , the touch sensor panel 100 is included outside thedisplay module 200. FIGS. 12a to 12c show that the touch detectiondevice of the touch sensor panel 100 is integrated in the touch sensingIC 150 mounted on the first PCB 160 for the touch sensor panel 100.

FIG. 12a shows that the pressure electrodes 450 and 460 attached to thedisplay module 200 are connected to the touch sensing IC 150 through afirst connector 121. As shown in FIG. 10a , in a mobile communicationdevice such as a smart phone, the touch sensing IC 150 is connected tothe second PCB 210 for the display module 200 through the firstconnector 121. The second PCB 210 may be electrically connected to themain board through a second connector 224. Therefore, through the firstconnector 121 and the second connector 224, the touch sensing IC 150 maytransmit and receive a signal to and from the CPU or AP for theoperation of the touch input device 1000.

Here, while FIG. 12a shows that the first electrode 450 is attached tothe display module 200 by the method shown in FIG. 11b , the firstelectrode 450 can be attached to the display module 200 by the methodshown in FIG. 11a . A conductive pattern may be printed on the secondPCB 210 in such a manner as to electrically connect the first electrode450 and the second electrode 460 to the touch sensing IC 150 through thefirst connector 121.

FIG. 12b shows that the pressure electrodes 450 and 460 attached to thedisplay module 200 are connected to the touch sensing IC 150 through athird connector 473. In FIG. 12b , the pressure electrodes 450 and 460may be connected to the main board for the operation of the touch inputdevice 1000 through the third connector 473, and in the future, may beconnected to the touch sensing IC 150 through the second connector 224and the first connector 121. Here, the pressure electrodes 450 and 460may be printed on the additional PCB 211 separated from the second PCB210. Otherwise, according to the embodiment, the pressure electrodes 450and 460 may be formed on the insulation layer 470 and may be connectedto the main board through the connector 473 by extending the conductivetrace, etc., from the pressure electrodes 450 and 460.

FIG. 12c shows that the pressure electrodes 450 and 460 are directlyconnected to the touch sensing IC 150 through a fourth connector 474. InFIG. 12c , the pressure electrodes 450 and 460 may be connected to thefirst PCB 160 through the fourth connector 474. A conductive pattern maybe printed on the first PCB 160 in such a manner as to electricallyconnect the fourth connector 474 to the touch sensing IC 150. As aresult, the pressure electrodes 450 and 460 may be connected to thetouch sensing IC 150 through the fourth connector 474. Here, thepressure electrodes 450 and 460 may be printed on the additional PCB 211separated from the second PCB 210. The fourth connector 474 may beinsulated from the additional PCB 211 so as not to be short-circuitedwith each other. Also, according to the embodiment, the pressureelectrodes 450 and 460 may be formed on the insulation layer 470 and maybe connected to the first PCB 160 through the connector 474 by extendingthe conductive trace, etc., from the pressure electrodes 450 and 460.

The connection method of FIGS. 12b and 12c can be applied to the casewhere the pressure electrode 450 and 460 are formed on the substrate 300as well as on the bottom surface of the display module 200.

FIGS. 12a to 12c have been described by assuming that a chip on board(COB) structure in which the touch sensing IC 150 is formed on the firstPCB 160. However, this is just an example. The present invention can beapplied to the chip on board (COB) structure in which the touch sensingIC 150 is mounted on the main board within the mounting space 310 of thetouch input device 1000. It will be apparent to those skilled in the artfrom the descriptions of FIGS. 12a to 12c that the connection of thepressure electrodes 450 and 460 through the connector can be alsoapplied to another embodiment.

The foregoing has described the pressure electrodes 450 and 460, that isto say, has described that the first electrode 450 constitutes onechannel as the drive electrode and the second electrode 460 constitutesone channel as the receiving electrode. However, this is just anexample. According to the embodiment, the drive electrode and thereceiving electrode constitute a plurality of channels respectively, sothat a plurality of pressure detection can be made based on themulti-touch.

FIGS. 13a to 13c show that the pressure electrode of the presentinvention constitutes the plurality of channels. FIG. 13a shows thefirst electrode 450-1 and 450-2 and the second electrode 460-1 and 460-2constitute two channels respectively. FIG. 13b shows that the firstelectrode 450 constitutes two channels 450-1 and 450-2 and the secondelectrode 460 constitutes one channel. FIG. 13c shows the firstelectrode 450-1 to 450-5 and the second electrode 460-1 to 460-5constitute five channels respectively.

FIGS. 13a to 13c show that the pressure electrode constitutes a singleor a plurality of channels. The pressure electrode may be comprised of asingle or a plurality of channels by a variety of methods. While FIGS.13a to 13c do not show that the pressure electrodes 450 and 460 areelectrically connected to the touch sensing IC 150, the pressureelectrodes 450 and 460 can be connected to the touch sensing IC 150 bythe method shown in FIGS. 12a to 12c and other methods.

FIG. 14 is a graph that, when an experiment where the central portion ofthe touch surface of the touch input device 1000 according to theembodiment of the present invention is pressed by the non-conductiveobject is performed, represents a capacitance change amount according toa gram force of the object. As shown in FIG. 14, the greater the forcewhich is applied to the central portion of the touch surface of thetouch input device 1000 according to the embodiment of the presentinvention, the greater the capacitance change amount of the pressureelectrode patterns 450 and 460 for detecting the pressure.

The foregoing has described the capacitance type detection module fordetecting the pressure. However, so long as the spacer layer 420 and 220and the pressure electrodes 450 and 460 (or electrode sheet 440) areused to detect the pressure, the touch input device 1000 according tothe embodiment of the present is able to use any type pressure detectionmodule.

Although embodiments of the present invention were described above,these are just examples and do not limit the present invention. Further,the present invention may be changed and modified in various ways,without departing from the essential features of the present invention,by those skilled in the art. For example, the components described indetail in the embodiments of the present invention may be modified.Further, differences due to the modification and application should beconstrued as being included in the scope and spirit of the presentinvention, which is described in the accompanying claims.

What is claimed is:
 1. A touch input device which detects a pressure ofa touch on a touch surface, the touch input device comprising: a displaymodule; a substrate for blocking electrical noise or for separating thedisplay module from a circuit board or battery for operation of thetouch input device; and a first electrode disposed on the display moduleand a second electrode disposed on the substrate, wherein a spacer layeris disposed between the first electrode and the second electrode,wherein a pressure magnitude of the touch is detected based on acapacitance between the first electrode and the second electrode, andthe capacitance is changed depending on the distance between the firstelectrode and the second electrode, wherein the display module is bentby the touch, and the distance between the first electrode and thesecond electrode is changed due to the bending of the display module,wherein the first electrode is disposed on a bendable surface of thedisplay module, and wherein the spacer layer is maintained with apredetermined thickness only by a supporting structure which is made ofinelastic material and located only in an edge portion of the substrate,and wherein the supporting structure is located between the displaymodule and the substrate which is under the display module, wherein thesecond electrode is positioned between a first insulation layer and asecond insulation layer, and the second electrode, together with thefirst insulation layer and the second insulation layer, is fixed as anintegral electrode sheet to the substrate.
 2. The touch input device ofclaim 1, wherein each of the first electrode and second electrodeconstitutes a plurality of channels.
 3. The touch input device of claim2, wherein a pressure of each of multi touches is detected by using theplurality of channels.
 4. The touch input device of claim 1, wherein thetouch surface is at least one of a top surface of the display module anda bottom surface of the substrate.
 5. The touch input device of claim 1,further comprising: a touch sensor panel which detects a position of thetouch when the touch occurs on the touch surface; and a first printedcircuit board on which a touch sensing circuit for the operation of thetouch sensor panel has been mounted, wherein the touch sensor panel isadhered to a surface of the display module, which is opposite to thesubstrate.
 6. The touch input device of claim 1, wherein the displaymodule further comprises a second printed circuit board on which acontrol circuit for the operation of the display panel has been mounted,and wherein the first electrode is attached to the display module insuch a manner as to be electrically connected to a conductive patternprinted on the second printed circuit board.
 7. The touch input deviceof claim 6, further comprising: a touch sensor panel which detects aposition of the touch when the touch occurs on the touch surface; and afirst printed circuit board on which a touch sensing circuit for theoperation of the touch sensor panel has been mounted, wherein the touchsensor panel is adhered to a surface of the display module, which isopposite to the substrate, and further comprising a connector between afirst printed circuit board and the second printed circuit board,wherein the electrode is electrically connected to the touch sensingcircuit through the connector.
 8. The touch input device of claim 5,wherein the display module further comprises a second printed circuitboard on which a control circuit for the operation of the display panelhas been mounted, wherein the first electrode is formed on an additionalcircuit board, further comprising a connector between the additionalcircuit board and the first printed circuit board, wherein the firstelectrode is electrically connected to the touch sensing circuit throughthe connector.
 9. The touch input device of claim 5, wherein the displaymodule further comprises a second printed circuit board on which acontrol circuit for the operation of the display panel has been mounted,wherein the first electrode is formed on an additional circuit board,further comprising: a first connector between the first printed circuitboard and the second printed circuit board; a second connector betweenthe second printed circuit board and a main board on which a centralprocessing unit for the operation of the touch input device has beenmounted; and a third connector between the additional circuit board andthe main board, wherein the first electrode is electrically connected tothe touch sensing circuit through the first connector, the secondconnector and the third connector.